Braking system of a vehicle with at least two steered and braked front axles and method for controlling or regulating a braking system

Abstract

The invention discloses a braking system (10) of a vehicle (8) with at least two steered and braked front axles, a first steered and braked front axle (VA1) and at least one second steered and braked front axle (VA2) and with at least one rear axle (HA), comprising: first braking means (1) configured for braking first wheels (VA1r, VA1l) of the first front axle (VA1) and for this purpose comprising first wheel brakes (VA1Br, VA1Bl) on the first wheels (VA1r, VA1l), second braking means (2) configured for braking second wheels (VA2r, VA2l) of the at least one second front axle (VA2) and for this purpose comprising second wheel brakes (VA2Br, VA2Bl) on the second wheels (VA2r, VA2l), and control or regulating means (5) configured to control or regulate the first braking means (1) and the second braking means (2). as recognition devices (7),which are configured to detect a significant oversteer situation of the vehicle (8) and, in the event of a detected significant oversteer situation, to generate an oversteer signal, wherein the control means (5), in particular control means of the vehicle dynamics control (ESP), are further configured to control or regulate the first brake means (1) and the second brake means (2) depending on the oversteer signal then generated in the event of a significant oversteer situation detected by the detection means (7).

Description

[0001] The invention relates to a braking system of a vehicle with at least two steered and braked front axles, a first steered and braked front axle and at least one second steered and braked front axle and with at least one rear axle, according to the preamble of claim 1, as well as a vehicle with such a braking system according to the preamble of claim 14, and a method for controlling or regulating a braking system, in particular comprising a vehicle dynamics control system (ESP), of a vehicle with at least two steered and braked front axles, a first steered front axle that can be braked by first braking means and at least one second steered front axle that can be braked by second braking means and with at least one rear axle according to claim 15.

[0002] For example, EP 3 707 058 B1 discloses a generic braking system for a vehicle with double front-wheel steering.

[0003] The objective is to provide a braking system and a method for controlling or regulating a braking system for a vehicle with double front-wheel steering, with which high driving stability is achieved. Furthermore, a vehicle with such a braking system is also to be provided. This objective is achieved according to claims 1, 14, and 15.

[0004] The dependent claims relate to advantageous embodiments of the subject matter of the independent claims. Disclosure of the invention

[0005] In a first aspect, the invention is based on a braking system of a vehicle with at least two steered and braked front axles, a first steered and braked front axle and at least one second steered and braked front axle and with at least one rear axle available, comprising: a) First braking means configured to brake first wheels of the first front axle and comprising first wheel brakes on the first wheels, c) Second braking means configured to brake second wheels of at least one second front axle and comprising wheel brakes on the second wheels, d) Control or regulating means configured to control or regulate the first braking means and the second braking means.

[0006] Viewed in the direction of travel of the vehicle, the first front axle is preferably arranged in front of at least one second front axle.

[0007] The braking system can include, in particular, electronic stability control (ESP) as a driver assistance system. The electronic stability control is configured for the targeted braking of individual wheels (individual wheel braking) to prevent the vehicle from skidding, especially in curves, during both oversteer and understeer. To enable the electronic stability control (ESP) to react to critical driving situations, the system compares a target state (driver request or autopilot request) with the actual driving situation. A steering angle sensor provides the target state with respect to the direction of travel. The engine management system, wheel speed sensors, and a Yaw rate sensor ( Yaw rateThe sensors (lateral acceleration) provide data on the current state (vehicle behavior). If a significant deviation of the driving state from the target state is detected, the electronic stability program (ESP) intervenes. For example, oversteer is corrected by braking an outside front wheel of the front axle, and understeer is corrected by braking an inside rear wheel of the rear axle.

[0008] The braking system, according to the invention, comprises: e) Detection means, in particular detection means of the vehicle dynamics control (ESP) of the braking system, which are configured to detect a significant oversteer situation of the vehicle and, in the event of a detected significant oversteer situation of the vehicle, to generate an oversteer signal, wherein f) the control means, in particular control means of the vehicle dynamics control (ESP), are further configured to control or regulate the first braking means and the second braking means depending on the oversteer signal then generated in the event of a significant oversteer situation detected by the detection means.

[0009] The control elements of the braking system can therefore include control elements of an electronic stability program (ESP), which interact with the detection elements in such a way that, in the event of a significant oversteer situation detected by the detection elements, the first and second braking elements are controlled by the control elements of the electronic stability program (ESP) depending on the generated oversteer signal. Consequently, the first braking elements on the first front axle and also the second braking elements on at least one second front axle are integrated into the electronic stability program (ESP) of the braking system.The (pneumatic or hydraulic) first service brake pressures in the first wheel brakes and the second service brake pressures in the second wheel brakes, and / or the first braking forces of the first wheel brakes and the second braking forces of the second wheel brakes, and / or the first brake slip of the first wheels and the second brake slip of the second wheels can preferably be controlled or regulated by the electronic stability program (ESP). By including at least one second front axle in the electronic stability program (ESP), the vehicle's driving stability is increased, especially in oversteer and understeer situations.

[0010] In particular, the braking system's control or regulation means can be configured to control or regulate at least one target braking parameter, depending on the override signal, which can influence the braking, braking effect, or deceleration of the vehicle. A target braking parameter can therefore be defined such that it influences the braking, braking effect, or deceleration of the vehicle when implemented. Target braking parameter can also mean that it is specified by the control or regulation means, particularly depending on a brake request signal from a brake force sensor. The brake force sensor can be a brake force sensor actuated by a driver's foot or an autopilot brake force sensor that automatically (autonomously) generates the brake request signal.

[0011] The target braking parameter can be at least one of the following braking parameters: a) A target braking pressure and / or a target braking force at at least one first wheel brake of the first front axle and / or at at least one second wheel brake of the at least one second front axle, and / or b) a target braking slip of at least one first wheel of the first front axle and / or at least one second wheel of the at least one second front axle.

[0012] Furthermore, the control or regulating means, the primary braking means and the secondary braking means of the braking system can be configured to achieve at least one target braking parameter. a) to control or regulate at least one first wheel brake and / or at least one first wheel, in particular at all first wheel brakes and / or at all first wheels individually, and b) to control or regulate at least one second wheel brake and / or at least one second wheel, in particular at all second wheel brakes and / or at all second wheels individually.

[0013] In this system, all wheels on the front axles are individually controlled (for driving dynamics). This applies, for example, to 4S4K braking systems. As a result of the individual wheel control, particularly on the first and second wheels of the first and second front axles, this variant is characterized by high driving stability. However, the complexity is relatively high due to the number of control components required.

[0014] The braking system's control or regulation elements, the primary braking elements, and the secondary braking elements can also be configured to control or regulate at least one target braking parameter on at least one primary wheel and / or at least one primary wheel brake and at least one secondary wheel and / or at least one secondary wheel brake on each side. In particular, all primary and secondary wheels are controlled separately on each side (in terms of vehicle dynamics). This applies, for example, to 4S2K braking systems. Since the number of control and regulation components required for implementing electronic stability control (ESP) is lower in this case, this variant is characterized by reduced hardware and software complexity.

[0015] The braking system can also have its control or regulating means, primary braking means, and secondary braking means configured to achieve at least one target braking parameter. a) to control or regulate at least one first wheel brake and / or at least one wheel, in particular at all first wheel brakes and / or at all first wheels individually, and b) to control or regulate the second wheel brakes and / or at the second wheels axle by axle or uniformly.

[0016] Axle-specific or uniform control means that the wheels or wheel brakes of the respective axle are controlled or regulated jointly, whereby in particular the at least one target braking parameter (target braking pressure, target braking force and / or target braking slip) is then (essentially) identical for all wheels of the respective front axle, here the at least one second front axle. This variant is characterized by a compromise between saving on control components on the at least one second front axle and increasing driving stability through wheel-specific control on the first front axle.

[0017] For example, in this variant, the first braking means can include first pneumatic wheel brakes, in particular first pneumatic service brake cylinders and a two-channel pressure control module on the first front axle to control or regulate the first service brake pressures in the first pneumatic service brake cylinders on the first wheels of the first front axle individually for each wheel. Similarly, in this variant, the second braking means on at least one second front axle can include second pneumatic wheel brakes, in particular second pneumatic service brake cylinders on the second wheels of the second front axle, as well as an electro-pneumatic single-channel pressure control module to control or regulate the second service brake pressures in the second pneumatic service brake cylinders on the second wheels of the second front axle axle-wise.

[0018] In this variant, the control or regulation means, the first braking means and the second braking means can be configured to control or regulate at least one second target braking parameter at the axle-wise or uniformly controllable second wheel brakes and / or at the uniformly controllable second wheels, depending on at least one first target braking parameter at the first wheel brake of the outer first wheel in the detected significant oversteer situation and / or at the outer first wheel in the detected significant oversteer situation, wherein this first target braking parameter is specified in particular by the vehicle dynamics control (ESP) in the detected significant oversteer situation.

[0019] This first target braking parameter, specified in the recognized significant oversteer situation, particularly by the vehicle dynamics control (ESP), includes, for example, the first target brake slip of the outer first wheel of the first front axle and / or the first target service brake pressure at the first wheel brake of the outer first wheel of the first front axle.

[0020] The at least one first target braking parameter, from which the at least one second target braking parameter is derived or controlled or regulated, is therefore preferably the first target brake slip of the outer first wheel of the first front axle specified in particular by the vehicle dynamics control (ESP) in the detected significant oversteer situation and / or the first target service brake pressure in the first wheel brake of the outer first wheel of the first front axle specified preferably by the vehicle dynamics control (ESP) in the detected significant oversteer situation.Since a significant oversteer situation of the vehicle always involves a certain rotation of the vehicle around its vertical axis (yaw), the position of the outermost wheel of the first front axle is related to the rotation of the vehicle in the significant oversteer situation and can be determined, for example, from the wheel speed signals of the wheel speed sensors of the first wheels.

[0021] Therefore, preferably the at least one second front axle with, for example, a 2S1K configuration is included in the vehicle dynamics control (ESP) of the braking system in such a way that, in particular in a detected significant oversteer situation, for example, the second target brake slip at the second wheels and / or the second service brake pressure in the second wheel brakes of the at least one second front axle is controlled or regulated uniformly or axle by axle, depending on the first target brake slip of the outer first wheel of the first front axle and / or depending on the first target service brake pressure in the first wheel brake of the outer first wheel of the first front axle.

[0022] This dependency can, for example, consist of calculating the second target brake slip at the second wheels and / or the second target service brake pressure at the second wheel brakes of the at least one second front axle by multiplying the first target brake slip of the outer first wheel of the first front axle and / or the first target service brake pressure in the first wheel brake of the outer wheel of the first front axle by a (particularly predetermined) factor. This factor is preferably greater than zero and (slightly) less than one, in particular only slightly less than one. The second wheels of the at least one second front axle are then braked axle by axle or uniformly, for example, with a relatively high second target brake slip in the detected significant oversteer situation, in order to reduce the lateral grip at this at least one second front axle.In combination with ESP intervention on the first front axle, specifically only on the outermost wheel in a curve, the vehicle's driving stability is significantly improved compared to a control strategy in which, for example, only the first front axle is included in the vehicle dynamics control (ESP), but not at least one second front axle.

[0023] The control or regulation devices, particularly in the form of an electronic brake control system with implemented control or regulation software, can also include routines of a vehicle dynamics control system (ESP), which may also include, for example, ABS control. For this purpose, at least one first wheel of the first front axle and / or at least one second wheel of at least one second front axle is each equipped with a wheel speed sensor, which then sends a wheel speed signal to the control or regulation device in order to control the brake slip of the respective first or second wheel.

[0024] The braking system can also be configured to detect significant oversteer and generate an oversteer signal when the vehicle's actual yaw rate, or a corresponding actual value, deviates from a target yaw rate, or a corresponding target value, by more than a predefined threshold or significantly. The target yaw rate can be set, for example, by the driver via the steering wheel or by an autopilot system via a target steering angle.

[0025] The braking system can also have control or regulation means, the first braking means and the second braking means configured to control or regulate the first braking means and the second braking means, in particular the at least one target braking parameter, in particular the at least one second target braking parameter on the at least one second front axle, depending on the deviation.

[0026] In other words, the at least one target braking parameter, in particular the at least one second target braking parameter, is adjusted at the second wheels and / or at the second wheel brakes depending on the deviation of the actual rotation rate from the target rotation rate, wherein the adjustment is greater the greater the deviation, and the adjustment is smaller the smaller the deviation, in particular if this deviation exceeds the threshold or is significant.

[0027] The significant oversteering situation can result in particular from: a) activation of the first and second braking means by the control or regulating means as part of a driver-dependent or driver-independent braking maneuver (e.g. braking by the autopilot system), and / or b) a driver-dependent or driver-independent steering maneuver (e.g. steering by the autopilot system).

[0028] The braking system may, for example, be or include an electro-pneumatic braking system, in particular an electronically controlled brake pressure system (EBS), an electro-hydraulic braking system and / or an electro-mechanical braking system.

[0029] Furthermore, the braking system can a) the detection means comprise at least one yaw rate sensor and / or at least one acceleration sensor, and / or b) the control means comprise at least one electronic control unit in which, in particular, routines of a vehicle dynamics control system are implemented, and / or c) the first braking means and / or the second braking means comprise pneumatic wheel brakes and an electro-pneumatic single-channel or dual-channel pressure control module on the first front axle and / or on the at least one second front axle, wherein c1) the single-channel pressure control module is configured and controlled or regulated by the control means to control or regulate the first and / or second wheel brakes and / or the first and / or second wheels, in particular the second wheel brakes and / or the second wheels of the at least one second front axle, axle by axle or uniformly,and c2) the two-channel pressure control module is configured and controlled or regulated by the control or regulation means to control or regulate the wheel brakes of the wheels, in particular the wheel brakes of all wheels of the first front axle individually.

[0030] In a second aspect, the invention discloses a vehicle, in particular a commercial vehicle, comprising a braking system as described above.

[0031] In a third aspect, the invention discloses a method for controlling or regulating a braking system, in particular one comprising vehicle dynamics control, of a vehicle with at least two steered and braked front axles, a first steered front axle that can be braked by first braking means, and at least a second steered front axle that can be braked by second braking means, and with at least one rear axle, wherein the first braking means are provided for braking first wheels of the first front axle and for this purpose first wheel brakes are provided on the first wheels, and the second braking means are provided for braking second wheels of the second front axle and for this purpose second wheel brakes are provided on the second wheels. The method then comprises, in particular within the framework of the vehicle dynamics control (ESP) of the braking system, at least the following steps: a) Check and detect whether a significant oversteer situation of the vehicle exists, and b) if a significant oversteer situation of the vehicle has been detected: b1) generate an oversteer signal, and b2) control or regulate the first braking means and the second braking means depending on the oversteer signal.

[0032] As already explained above regarding the braking system, this means that both front axles and, in particular, at least one second front axle are included in the vehicle dynamics control (ESP) of the braking system in the event of a detected significant oversteer situation.

[0033] In this method, at least one target braking parameter is preferably controlled or regulated depending on the override signal, which influences or can influence braking, braking effect or deceleration of the vehicle.

[0034] The procedure allows for at least one target braking parameter. a) are individually controlled or regulated at at least one first wheel brake and / or at at least one first wheel, and b) are individually controlled or regulated at at least one second wheel brake and / or at at least one second wheel.

[0035] Alternatively, in the method, at least one braking parameter or at least one target braking parameter can be controlled or regulated side by side at at least one first wheel and / or at at least one first wheel brake and at at least one second wheel and / or at least one second wheel brake.

[0036] Alternatively, the procedure can include at least one braking parameter a) are individually controlled or regulated at at least one first wheel brake and / or at at least one first wheel, and b) are controlled or regulated axle by axle or uniformly at the second wheel brakes and / or at the second wheels.

[0037] In this variant, at least one second target braking parameter can be controlled or regulated at the axle-wise or uniformly controllable second wheel brakes and / or at the uniformly controllable second wheels depending on at least one first target braking parameter at the first wheel brake of the outer first wheel in the detected significant oversteer situation and / or at the outer first wheel in the detected significant oversteer situation, wherein this first target braking parameter is specified in particular by the vehicle dynamics control (ESP) in the detected significant oversteer situation.

[0038] The procedure can also detect a significant oversteer situation of the vehicle and then generate the oversteer signal if a recorded actual rotation rate or an actual value correlated with it deviates from a target rotation rate or a target value correlated with it by more than a predefined threshold.

[0039] In this method, the first braking means and the second braking means, in particular at least one braking parameter, can also be controlled or regulated depending on the deviation from the specified threshold.

[0040] Furthermore, the invention also includes a computer program with program code that causes the braking system, in particular the vehicle dynamics control (ESP) of the braking system, to execute the method described above when the computer program is executed on a processor. drawing

[0041] Exemplary embodiments of the invention are described below with reference to the accompanying figures. The figures show: Fig. 1 a schematic representation of a preferred embodiment of a braking system of a vehicle according to the invention; Fig. 2 a flow chart of a preferred embodiment of a method for controlling or regulating the braking system of Fig. 1 . Description of the exemplary implementations

[0042] Fig. 1 Figure 1 shows a schematic representation of a preferred embodiment of a braking system 10 of a vehicle 8 according to the invention, which is, for example, an electro-pneumatic service braking system of a heavy commercial vehicle.

[0043] For example, vehicle 8 has two steered and braked front axles, a first steered and braked front axle VA1 and a second steered and braked front axle VA2, as well as a rear axle HA.

[0044] Furthermore, the braking system has 10 first brake means 1, which are configured to brake wheels VA1r, VA1l, of the first front axle VA1 and for this purpose has first wheel brakes VA1Br, VA1Bl on the first wheels VARr, VARI of the first front axle VA1, as well as second brake means 2, which are configured to brake wheels VA2r, VA2l of the second front axle VA2 and for this purpose has second wheel brakes VA2Br, VA2BI on the second wheels VA2r, VA2l of the second front axle VA2.

[0045] The first braking means 1 here include, for example, first pneumatic wheel brakes VA1Br, VA1Bl, in particular first pneumatic service brake cylinders and a two-channel pressure control module 3 on the first front axle VA1, in order to control or regulate individually wheel-specific first service brake pressures P1r, P1l in the first wheel brakes VA1Br, VA1Bl on the wheels VA1r, VA1l of the first front axle VA1.

[0046] The second braking means 2 here, for example, have second pneumatic wheel brakes VA2Br, VA2BI, in particular second pneumatic service brake cylinders on the wheels VA2r, VA2l of the second front axle VA2, as well as an electro-pneumatic single-channel pressure control module 4 on the second front axle VA2, in order to control or regulate a second, then only axle-wise controllable and uniform service brake pressure P2 in the second wheel brakes VA2Br, VA2BI on the wheels VA2r, VA2l of the second front axle VA2.

[0047] Furthermore, the braking system comprises 10 of Fig. 1 Control or regulation device 5, in particular in the form of an electronic brake control system with implemented control or regulation software. This control or regulation software includes, in particular, routines of a vehicle dynamics control system (ESP), which also includes, for example, ABS control. For this purpose, for example, the wheels VA1r, VA1l of the first front axle VA1 and optionally also the wheels VA2r, VA2l of the second front axle VA2 are each equipped with a wheel speed sensor, which then reports a wheel speed signal to control or regulation device 5 in order to control the brake slip of the wheels VA1r, VA1l of the first front axle VA1 and optionally also the wheels VA2r, VA2l of the second front axle VA2.

[0048] The control or regulating means 5 control or regulate the two-channel pressure control module 3 on the first front axle VA1 and the single-channel pressure control module 4 on the second front axle VA2, in order to control or regulate at least one brake parameter each, here on the first front axle VA1, for example, the first brake slips S1r, S1l and the first service brake pressures P1r, P1l in the first pneumatic wheel brakes VA1Br, VA1Bl individually for each wheel, and in order to control or regulate the then uniform second target brake slip S2 on the second wheels VA2r, VA2l and the then also uniform second brake pressure P2 in the second wheel brakes VA2Br, VA2BI axle by axle.

[0049] The 2-channel pressure control module 3 on the first front axle VA1 comprises a first channel, which is used, for example, to control or regulate the first right brake pressure P1r in the first right wheel brake VA1Br of the first right wheel VA1r of the first front axle VA1, and a second channel, which is used, for example, to control or regulate the first left service brake pressure P1l of the first left wheel brake VA1Bl of the first left wheel VA1l of the first front axle VA1. Furthermore, the first right brake slip S1r of the first right wheel VA1r and the first left brake slip S1l of the first left wheel VA1l of the first front axle VA1 can be individually controlled in the first channel of the 2-channel pressure control module 3.For this purpose, the 2-channel pressure control module 3 can be controlled by the control or regulating means 5, in which, for example, the reference speed necessary for ABS control is calculated from the wheel speed signals of the wheel speed sensors.

[0050] The single-channel pressure control module 4 on the second front axle VA2, however, preferably comprises only a single channel, which is provided for the uniform control or regulation of the second brake pressure P2 of the second wheel brakes VA2Br, VA2l on the second wheels VA2r, VA2l of the second front axle VA2. The second brake slip S2 of the second wheels VA2r, VA2l for the second front axle VA2 can also be controlled axle-wise and therefore uniformly in this single channel.

[0051] The two pressure control modules 3, 4 each have, in a known manner, an integrated electronic control, an inlet-outlet valve combination controlled by the electronic control and a pneumatically controlled relay valve, for which the inlet-outlet valve combination generates a pneumatic control pressure.

[0052] The brake system 10 also includes a brake force sensor 6, which generates a brake request signal, representing, for example, a driver's braking request. The brake request signal from the brake force sensor 6 is processed by the control or regulating devices 5 to generate electrical brake signals for each axle for the pressure control modules 3 and 4, which represent the respective target service brake pressures for each axle: for the first front axle VA1, the target service brake pressures P1r and P1l; for the second front axle, P2; and for the rear axle, P2.

[0053] For example, a two-channel pressure control module (not shown here) is also arranged on the rear axle to generate regulated service brake pressures for the wheel brakes of the rear axle (HA) depending on the brake request signal.

[0054] Depending on the electrical brake signals, the electronic controllers integrated into pressure control modules 3 and 4 then control the inlet / outlet valve combination for each channel to modulate actual brake pressures P1r-actual, P1l-actual, and P2-actual at an output of the relay valves. These actual brake pressures are then measured by an integrated pressure sensor for each channel and reported to the integrated electronic controller for comparison with the target brake pressures P1r-target, P1l-target, and P2-target. Brake pressure control routines are implemented in the integrated electronic controller for this purpose.

[0055] Furthermore, the braking system comprises 10 detection means 7, in particular detection means of the vehicle dynamics control (ESP), which are configured to detect a significant oversteer situation of the vehicle 8 and, in the event of a detected significant oversteer situation of the vehicle 8, to generate an oversteer signal. These detection means 7 can include, for example, evaluation electronics integrated here into the control means 5, as well as, for example, a yaw rate sensor that interacts with the evaluation electronics to generate the oversteer signal when the actual yaw rate of the vehicle 8, as detected by the yaw rate sensor, deviates from a target yaw rate by more than a predetermined threshold. The target yaw rate can be specified, for example, by a driver of the vehicle 8 through a steering angle of a steering wheel operated by him or by an autopilot system.

[0056] The control or regulation means 5 then control or regulate the single-channel pressure control module 4 on the second front axle VA2, for example, to uniformly control or regulate a second target brake slip S2-target at the second wheels VA2r, VA2l of the second front axle VA2, depending on the first target brake slip S1l-target of the then outer first wheel VA1l of the first front axle VA1, which is specified by the vehicle dynamics control (ESP) in the detected significant oversteer situation. Fig. 1 In the identified significant oversteer situation of vehicle 8, for example, the first left wheel VA1l represents the outer wheel of the first front axle VA1.

[0057] This first target brake slip S1l-target of the outer wheel VA1l of the first front axle VA1 in the detected significant oversteer situation is preferably determined by the ABS control integrated into the vehicle dynamics control (ESP) of the control and regulation means 5 and then implemented by the vehicle dynamics control (ESP) through the two-channel pressure control module 3.

[0058] Alternatively or additionally, it can be provided that the control or regulating means 5 controls or regulates the single-channel pressure control module 4 on the second front axle VA2 in the detected significant oversteer situation in order to control or regulate the second (uniform) target service brake pressure P2-target in the second wheel brakes VA2Br, VA2l of the second front axle VA2 depending on the first target service brake pressure P1l-target of the first wheel VA1l on the outside of the curve specified by the vehicle dynamics control ESP in the detected significant oversteer situation.

[0059] This dependency can, for example, consist of the uniform second target brake slip S2-target at all second wheels VA2r, VA2l and / or the uniform second target brake pressure P2-target at all second wheel brakes VA2Br, VA2BI of the second front axle VA2 being calculated by multiplying the first target brake slip S1l-target of the outermost (here left) first wheel VA1l of the first front axle VA1 and / or the first target brake pressure P1l-target at the first wheel brake VA1Bl of the outermost first wheel VA1l of the first front axle VA1 by a specifically defined factor. The dependency(ies) can then, for example, be represented in a characteristic map stored in a memory area of ​​the control or regulation system 5.

[0060] This factor is preferably greater than zero and less than one, and preferably slightly less than one. In the detected significant oversteer situation of the vehicle 8, the second wheels VA2r, VA2l of the second front axle VA2 are then braked, for example, with a uniform and, due to the close coupling here with the first target brake slip S1l of the first outside wheel VA1l, with a relatively high second target brake slip S2-target. This reduces the lateral grip of the second wheels VA2r, VA2l of the second front axle VA2, which counteracts the oversteer situation.

[0061] In combination with the activated vehicle dynamics control (ESP) on the first front axle VA1 as a result of the detected significant oversteer situation of the vehicle 8, in particular only on the outer first wheel VA1l, the driving stability of the vehicle is significantly improved compared to a control strategy in which, for example, only the first front axle VA1 is included in the vehicle dynamics control (ESP), but not the second front axle VA2.

[0062] Fig. 2 shows a flowchart of a preferred embodiment of a method for controlling or regulating the braking system of Fig. 1 . The software routines according to which the procedure runs are preferably integrated into the vehicle dynamics control (ESP) of the brake system 10.

[0063] After the START, the procedure includes, in step 100, checking and detecting whether a significant oversteer situation of vehicle 8 exists. If this is not the case ("NO"), the procedure loops back to the START. However, if this is the case ("YES"), the oversteer signal is generated in step 200.

[0064] In response to the overdrive signal, the control or regulating means 5 control or regulate the single-channel pressure control module 4 and the dual-channel pressure control module 4 in a step 300 in order to reduce or completely eliminate the detected significant overdrive situation.

[0065] This can include the control or regulation means 5 controlling or regulating the two-channel pressure control module 3 on the first front axle VA1, for example, to regulate only the first actual brake slip S1l at the outer first wheel VA1l-actual of the first front axle VA1 to a target brake slip VA1l-target, with which the oversteer situation can be reduced or eliminated. Furthermore, this can include the control or regulation means 5 controlling or regulating the single-channel pressure control module 4 on the second front axle VA2, in order to uniformly control or regulate the second target brake slip S2-target at the second wheels VA2r, VA2l of the second front axle VA2, depending on the first target brake slip S1l-target of the outer first wheel VA1l of the first front axle VA1 in the detected significant oversteer situation.

[0066] As described above, this dependency can, for example, consist of calculating the target brake slip S2-target at the second wheels VA2r, VA2l of the second front axle VA2 by multiplying the first target brake slip S1l of the outermost wheel VA1l of the first front axle VA1 by a predefined factor. In the detected significant oversteer situation, the second wheels VA2r, VA2l of the second front axle VA2 are then braked axle by axle, for example, with a relatively high target brake slip S2-target, in order to reduce the lateral grip of the second wheels VA2r, VA2l on this second front axle VA2. In combination with the activated vehicle dynamics control (ESP) at the first front axle VA1 as a result of the detected significant oversteer situation of the vehicle 8, specifically only at the outermost wheel VA1l, the oversteer situation of the vehicle 8 is reduced. Reference numeral list (part of the description)

[0067] 1. First brake medium 2. Second brake medium 3. Dual-channel pressure control module 4. Single-channel pressure control module 5. Control or regulating medium 6. Brake force sensor 7. Detection medium 8. Vehicle 10. Braking system 100-300 Procedure steps HA Rear axle VA1 First front axle VA1 First wheel right VA1 First wheel left VA1 First wheel brake right VA1 First wheel brake left P1 First service brake pressure right P1 First service brake pressure left S1 First brake slip right S1 First brake slip left VA2 Second front axle VA2 Second wheel right VA2 Second wheel left VA2 Second wheel brake right VA2B Second wheel brake left P2 Second service brake pressure S2 Second brake slip Target Target value Actual value

Claims

1. Braking system (10) of a vehicle (8) with at least two steered and braked front axles, a first steered and braked front axle (VA1) and at least one second steered and braked front axle (VA2) and with at least one rear axle (HA), comprising: a) first braking means (1) configured for braking first wheels (VA1r, VA1l) of the first front axle (VA1) and for this purpose comprising first wheel brakes (VA1Br, VA1Bl) on the first wheels (VA1r, VA1l), c) second braking means (2) configured for braking second wheels (VA2r, VA2I) of the at least one second front axle (VA2) and for this purpose comprising second wheel brakes (VA2Br, VA2BI) on the second wheels (VA2r, VA2l), d) control or regulating means (5) configured to control the first braking means (1) and the second braking means (2) To be able to control or rules characterized by the fact thatit further comprises: e) detection means (7), in particular detection means of a vehicle dynamics control (ESP) of the braking system (10), which are configured to detect a significant oversteer situation of the vehicle (8) and, in the event of a detected significant oversteer situation, to generate an oversteer signal, wherein f) the control means (5), in particular control means of the vehicle dynamics control (ESP), are further configured to control or regulate the first braking means (1) and the second braking means (2) depending on the oversteer signal then generated, in the event of a significant oversteer situation detected by the detection means (7).

2. Braking system according to claim 1, characterized by the fact thatthe control or regulating means (5) are configured to control or regulate at least one target braking parameter (P1r-target, P1l-target, P2-target, S1r-target, S1l-target, S2-target) depending on the override signal, which can influence braking, braking effect or deceleration of the vehicle (8).

3. Braking system according to claim 2, characterized by the fact that The target braking parameter is at least one of the following braking parameters: a) A target braking pressure (P1r-target, P1l-target, P2-target) and / or a target braking force at at least one first wheel brake (VA1Br, VA1l) of the first front axle (VA1) and / or at at least one second wheel brake (VA2Br, VA2BI) of the at least one second front axle (VA2), and / or b) a target braking slip (S1r-target, S1l-target, S2-target) of at least one first wheel (VA1r, VA1l) of the first front axle (VA1) and / or at least one second wheel (VA2r, VA2I) of the at least one second front axle (VA2).

4. Braking system according to claim 2 or 3, characterized by the fact thatthe control or regulating means (5), the first braking means (1) and the second braking means (2) are configured to control or regulate the at least one target braking parameter (P1r-target, P1l-target, P2-target, S1r-target, S1l-target, S2-target) a) at at least one first wheel brake (VA1Br, VA1Bl) and / or at at least one first wheel (VA1r, VA1l), in particular at all first wheel brakes and / or at all first wheels individually, and b) at at least one second wheel brake (VA2Br, VA2BI) and / or at at least one second wheel (VA2r, VA2l), in particular at all second wheel brakes and / or at all second wheels individually.

5. Braking system according to claim 2 or 3, characterized by the fact thatthe control or regulating means (5), the first braking means (1) and the second braking means (2) are configured to control or regulate the at least one target braking parameter (P1r-target, P1l-target, P2-target, S1r-target, S1l-target, S2-target) on at least one first wheel (VA1r, VA1l) and / or on at least one first wheel brake (VA1Br, VA1Bl) and on at least one second wheel (VA2r, VA2I) and / or on at least one second wheel brake (VA2Br, VA2BI) side by side.

6. Braking system according to claim 2 or 3, characterized by the fact thatthe control or regulating means (5), the first braking means (1) and the second braking means (2) are configured to control or regulate the at least one target braking parameter (P1r-target, P1l-target, P2-target, S1r-target, S1l-target, S2-target) a) on at least one first wheel brake (VA1Bl) and / or on at least one first wheel (VA1r, VA1l) individually for each wheel, and b) on the second wheel brakes (VA2Br, VA2BI) and / or on the second wheels (VA2r, VA2I) axle by axle or uniformly.

7. Braking system according to claim 6, characterized by the fact thatthe control or regulating means (5), the first braking means (1) and the second braking means (2) are configured to control or regulate the at least one second target braking parameter (P2-target, S2-target) at the axle-wise or uniformly controllable second wheel brakes (VA2Br, VA2BI) and / or at the uniformly controllable second wheels (VA2r, VA2I) depending on at least one first target braking parameter (P1r-target, P1l-target, S1r-target, S1l-target) at the first wheel brake (VA1Bl) of the outer first wheel (VA1l) in the detected significant oversteer situation and / or at the outer first wheel (VA1l) in the detected significant oversteer situation, wherein this first target braking parameter (P1r-target, P1l-target, S1r-target, S1l-target) in the detected significant oversteer situation is specified in particular by the vehicle dynamics control (ESP).

8. Braking system according to one of the preceding claims, characterized by the fact thatthe detection means (7) are configured to detect the significant oversteer situation of the vehicle (8) and then to generate the oversteer signal when a detected actual rotation rate or an actual value correlated with it deviates from a target rotation rate or a target value correlated with it by more than a predetermined threshold or significantly.

9. Braking system according to claim 8, characterized by the fact that the control or regulating means (5), the first braking means (1) and the second braking means (2) are configured to control or regulate the first braking means and the second braking means, preferably the at least one target braking parameter (P1r-target, P1l-target, P2-target, S1r-target, S1l-target, S2-target), in particular the at least one second target braking parameter (P2-target, S2-target) depending on the deviation.

10. Braking system according to one of the preceding claims, characterized by the fact that It includes electronic stability program (ESP).

11. Braking system according to one of the preceding claims, characterized by the fact that The significant oversteer situation results: a) from activation of the first braking means (1) and the second braking means (2) by the control or regulation means (5) during driver-dependent or driver-independent braking, and / or b) from a driver-dependent or driver-independent steering maneuver.

12. Braking system according to one of the preceding claims, characterized by the fact that It is or includes an electro-pneumatic braking system, an electro-hydraulic braking system and / or an electro-mechanical braking system.

13. Braking system according to one of the preceding claims, characterized by the fact thata) the detection means (7) comprise at least one yaw rate sensor and / or at least one acceleration sensor, and / or b) the control means (5) comprise at least one electronic control unit in which, in particular, routines of a vehicle dynamics control system are implemented, and / or c) the first braking means (1) and / or the second braking means (2) comprise pneumatic wheel brakes and an electro-pneumatic single-channel pressure control module (4) or a multi-channel pressure control module (3) on the first front axle (VA1) and / or on the at least one second front axle (VA2), wherein c1) the single-channel pressure control module (4) is configured and controlled by the control means (5) to control the first and / or second wheel brakes and / or the first and / or second wheels, in particular the second wheel brakes (VA2Br, VA2BI) of the second wheels (VA2r, VA2I) of the at least one second front axle (VA2) and / or the second wheels (VA2r,VA2I) axle-wise or uniformly, and c2) the multi-channel pressure control module (3) is configured and controlled or regulated by the control or regulating means (5) to control or regulate at least one first and / or second wheel brake and / or at least one first and / or second wheel, in particular the first wheel brakes (VA1Br, VA1Br) and / or the first wheels (VA1l, VA1r) individually.

14. Vehicle, in particular commercial vehicle, comprising a braking system according to one of the preceding claims.

15. Method for controlling or regulating a braking system (10) of a vehicle (8) having at least two steered and braked front axles, in particular an electronic stability program (ESP), a first steered front axle (VA1) that can be braked by first braking means (1), and at least one second steered front axle (VA2) that can be braked by second braking means (2), and at least one rear axle (HA), wherein the first braking means (1) are provided for braking first wheels (VA1r, VA1l) of the first front axle (VA1) and for this purpose first wheel brakes (VA1Br, VA1Bl) are provided on the first wheels (VA1r, VA1l), and the second braking means (2) are provided for braking second wheels (VA2r, VA2l) of the at least one second front axle (VA2) and for this purpose second wheel brakes (VA2Br, VA2BI) are provided on the second wheels (VA2r, VA2I). characterized by the fact thatIn particular, within the framework of vehicle dynamics control (ESP), it includes at least the following steps: a) checking and detecting whether a significant oversteer situation of the vehicle (8) exists, and b) if a significant oversteer situation of the vehicle (8) has been detected: b1) generating an oversteer signal, and b2) controlling or regulating the first braking means (1) and the second braking means (2) depending on the oversteer signal.

16. Method according to claim 15, characterized by the fact that at least one target braking parameter (P1r-target, P1l-target, P2-target, S1r-target, S1l-target, S2-target) is controlled or regulated depending on the override signal, which influences or can influence braking, braking effect or deceleration of the vehicle (8).

17. Method according to claim 16, characterized by the fact thatwhich at least one target braking parameter (P1r-target, P1l-target, P2-target, S1r-target, S1l-target, S2-target) a) is individually controlled or regulated at at least one first wheel brake (VA1Br, VA1Bl) and / or at at least one first wheel (VA1r, VA1l), and b) is individually controlled or regulated at at least one second wheel brake (VA2Br, VA2BI) and / or at at least one second wheel (VA2r, VA2I).

18. Method according to claim 16, characterized by the fact that which at least one target braking parameter (P1r-target, P1l-target, P2-target, S1r-target, S1l-target, S2-target) is controlled or regulated side by side at at least one first wheel (VA1r, VA1I) and / or at at least one first wheel brake (VA1Br, VA1Bl) and at at least one second wheel (VA2r, VA2I) and / or at least one second wheel brake (VA2Br, VA2BI).

19. Method according to claim 16, characterized by the fact thatwhich at least one target braking parameter (P1r-target, P1l-target, P2-target, S1r-target, S1l-target, S2-target) a) is individually controlled or regulated at at least one first wheel brake (VA1Bl) and / or at at least one first wheel (VA1r, VA1l), and b) is controlled or regulated axle by axle or uniformly at the second wheel brakes (VA2Br, VA2BI) and / or at the second wheels (VA2r, VA2I).

20. Method according to claim 19, characterized by the fact thatat least one second target braking parameter (P2-target, S2-target) at the axle-wise or uniformly controllable second wheel brakes (VA2Br, VA2BI) and / or at the uniformly controllable second wheels (VA2r, VA2I) depending on at least one first target braking parameter (P1r-target, P1l-target, S1r-target, S1l-target) at the first wheel brake (VA1Bl) of the outer first wheel (VA1l) in the detected significant oversteer situation and / or at the outer first wheel (VA1l) in the detected significant oversteer situation, wherein this first target braking parameter (P1r-target, P1l-target, S1r-target, S1l-target) is specified in the detected significant oversteer situation in particular by the vehicle dynamics control (ESP). becomes.

21. Method according to any one of claims 15 to 20, characterized by the fact thatthe significant oversteer situation of the vehicle (8) is detected and then the oversteer signal is generated when a detected actual rotation rate or an actual value correlated with it deviates from a target rotation rate or from a target value correlated with it by more than a predetermined threshold.

22. Method according to claim 21, characterized by the fact that which at least one target braking parameter (P1r-target, P1l-target, P2-target, S1r-target, S1l-target, S2-target), in particular at least one second target braking parameter (P2-target, S2-target) is controlled or regulated depending on the deviation.

Images